They're aiming to perfect their support for M1/M2 prior to working on the M3 and later models. Seems like a sensible choice, given that even a baseline M1 or M2 Mac is still a highly compelling device for a vast majority of uses. And Asahi will become more relevant as these devices cease to be supported by newer releases of macOS.
>a baseline M1 or M2 Mac is still a highly compelling device for a vast majority of uses.
Maybe in 2020. Lenovo released an ARM chromebook this summer which has benchmark performance of M1/M2 chips and is perfectly supported by Linux (ChromeOS) out of the box.